A Cloud Chamber Investigation of Interactions at Energies Greater than 50 BEV

Author: Jacobs, Earl Donald

Year: 1961

Degree: Dissertation (Ph.D.)

Advisors: Anderson, Carl D.; Cowan, Eugene W.

Committee Member: Unknown, Unknown

Option: Physics

DOI: 10.7907/0Q79-KG30

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document.

An experiment to measure the inelastic scattering cross-section for nucleons with energies greater than 50 BEV on Iron has been carried out using a large multiplate cloud chamber as the detector and the cosmic-ray flux at Pasadena as the source of nucleons. This cross-section has been found to be 0.56 ± .07 barns and the corresponding nucleon-nucleon cross-section (averaged over protons and neutrons) to be 18 ± 5 mb. The average energy of the events included in the measurement is estimated at 250 BEV. These results have been compared with the inelastic scattering cross-section data available for energies above the [...] meson threshold.

An analysis has been made of the angular distribution of N-rays having energy greater than 50 BEV to determine the absorption mean free path in the atmosphere. Also it is shown that the neutral to charged particle ratio at a known depth in the atmosphere and the ratio of the mean free path for absorption to the mean free path for interaction are related to the average elasticity in nucleon-nucleon collisions, the former setting a lower limit and the latter, an upper limit. The absorption mean free path in the atmosphere is found to be 115 ± 15 gm/cm2 and the elasticity is estimated at (0.27 ± .06) [...] 0.45.

Files